Androgen deprivation therapy (ADT) is considered standard of care for prostate cancer. However, changes in the patients metabolism are usually seen as a result of hormone therapy. These changes include increased fat mass, decreased lean mass, weight gain, high blood cholesterol, increased incidence of diabetes, and possibly increased incidence of cardiac events such as heart attack. The researchers of this trial would like to learn if these change in body mass are affected by the presence of brown fat in the body. Brown fat is made up of fat cells that are stored in the body and generate heat to control body temperature. Levels of brown fat are at the highest in newborn babies and decrease over time into adulthood. The researchers of this trial would like to learn more about these changes in metabolism during prostate cancer treatment by studying the changes in brown fat during the first 12 months of hormone therapy.